From 6893c19a8b81a399953edbf26aaef6e714a7ab0e Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Mon, 20 Jun 2016 10:36:29 -0600 Subject: [PATCH] Make "bt N" print correct number of frames when using a frame filter PR python/16497 notes that using "bt" with a positive argument prints the wrong number of frames when a frame filter is in use. Also, in this case, the non-frame-filter path will print a message about "More stack frames" when there are more; but this is not done in the frame-filter case. The first problem is that backtrace_command_1 passes the wrong value to apply_ext_lang_frame_filter -- that function takes the final frame's number as an argument, but backtrace_command_1 passes the count, which is off by one. The solution to the second problem is to have the C stack-printing code stop at the correct number of frames and then print the message. Tested using the buildbot. ChangeLog 2018-02-26 Tom Tromey PR python/16497: * stack.c (backtrace_command_1): Set PRINT_MORE_FRAMES flag. Fix off-by-one in py_end computation. * python/py-framefilter.c (gdbpy_apply_frame_filter): Handle PRINT_MORE_FRAMES. * extension.h (enum frame_filter_flags) : New constant. 2018-02-26 Tom Tromey PR python/16497: * gdb.python/py-framefilter.exp: Update test. --- gdb/ChangeLog | 10 +++++++++ gdb/extension.h | 3 +++ gdb/python/py-framefilter.c | 25 +++++++++++++++++++++ gdb/stack.c | 6 ++++- gdb/testsuite/ChangeLog | 5 +++++ gdb/testsuite/gdb.python/py-framefilter.exp | 2 +- 6 files changed, 49 insertions(+), 2 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 0897d59d89..906d14c191 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,13 @@ +2018-02-26 Tom Tromey + + PR python/16497: + * stack.c (backtrace_command_1): Set PRINT_MORE_FRAMES flag. Fix + off-by-one in py_end computation. + * python/py-framefilter.c (gdbpy_apply_frame_filter): Handle + PRINT_MORE_FRAMES. + * extension.h (enum frame_filter_flags) : New + constant. + 2018-02-26 Tom Tromey * dwarf2read.c (struct variant_field): New. diff --git a/gdb/extension.h b/gdb/extension.h index effa5bbffe..7375d72a64 100644 --- a/gdb/extension.h +++ b/gdb/extension.h @@ -100,6 +100,9 @@ enum frame_filter_flags /* Set this flag if frame locals are to be printed. */ PRINT_LOCALS = 8, + + /* Set this flag if a "More frames" message is to be printed. */ + PRINT_MORE_FRAMES = 16, }; /* A choice of the different frame argument printing strategies that diff --git a/gdb/python/py-framefilter.c b/gdb/python/py-framefilter.c index e887849c36..3a3fb97c6c 100644 --- a/gdb/python/py-framefilter.c +++ b/gdb/python/py-framefilter.c @@ -1355,6 +1355,18 @@ gdbpy_apply_frame_filter (const struct extension_language_defn *extlang, gdbpy_enter enter_py (gdbarch, current_language); + /* When we're limiting the number of frames, be careful to request + one extra frame, so that we can print a message if there are more + frames. */ + int frame_countdown = -1; + if ((flags & PRINT_MORE_FRAMES) != 0 && frame_low >= 0 && frame_high >= 0) + { + ++frame_high; + /* This has an extra +1 because it is checked before a frame is + printed. */ + frame_countdown = frame_high - frame_low + 1; + } + gdbpy_ref<> iterable (bootstrap_python_frame_filters (frame, frame_low, frame_high)); @@ -1402,6 +1414,19 @@ gdbpy_apply_frame_filter (const struct extension_language_defn *extlang, break; } + if (frame_countdown != -1) + { + gdb_assert ((flags & PRINT_MORE_FRAMES) != 0); + --frame_countdown; + if (frame_countdown == 0) + { + /* We've printed all the frames we were asked to + print, but more frames existed. */ + printf_filtered (_("(More stack frames follow...)\n")); + break; + } + } + success = py_print_frame (item.get (), flags, args_type, out, 0, levels_printed.get ()); diff --git a/gdb/stack.c b/gdb/stack.c index 9993ae654a..4481cc4c6a 100644 --- a/gdb/stack.c +++ b/gdb/stack.c @@ -1744,7 +1744,9 @@ backtrace_command_1 (const char *count_exp, int show_locals, int no_filters, else { py_start = 0; - py_end = count; + /* The argument to apply_ext_lang_frame_filter is the number + of the final frame to print, and frames start at 0. */ + py_end = count - 1; } } else @@ -1778,6 +1780,8 @@ backtrace_command_1 (const char *count_exp, int show_locals, int no_filters, if (show_locals) flags |= PRINT_LOCALS; + if (from_tty) + flags |= PRINT_MORE_FRAMES; if (!strcmp (print_frame_arguments, "scalars")) arg_type = CLI_SCALAR_VALUES; diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 755fe94c8b..be173ec34b 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2018-02-26 Tom Tromey + + PR python/16497: + * gdb.python/py-framefilter.exp: Update test. + 2018-02-26 Tom Tromey * gdb.dwarf2/variant.c: New file. diff --git a/gdb/testsuite/gdb.python/py-framefilter.exp b/gdb/testsuite/gdb.python/py-framefilter.exp index 7c72c983d2..7e02e9d701 100644 --- a/gdb/testsuite/gdb.python/py-framefilter.exp +++ b/gdb/testsuite/gdb.python/py-framefilter.exp @@ -149,7 +149,7 @@ gdb_test "bt -2" \ ".*#26.*func5.*#27.*in main \\(\\).*" \ "bt -2 with frame-filter Reverse disabled" gdb_test "bt 3" \ - ".*#0.*end_func.*#1.*in funca \\(\\).*#2.*in funcb \\(j=10\\).*" \ + ".*#0.*end_func.*#1.*in funca \\(\\).*#2.*in funcb \\(j=10\\)\[^#\]*More stack frames follow.*" \ "bt 3 with frame-filter Reverse disabled" gdb_test "bt no-filter full" \ ".*#0.*end_func.*str = $hex \"The End\".*st2 = $hex \"Is Near\".*b = 12.*c = 5.*#1.*in funca \\(\\).*#2.*in funcb \\(j=10\\).*bar = \{a = 42, b = 84\}.*" \ -- 2.34.1